Photographic camera



1.BECKER[ PHOTOGRAPHIC CAMERA.

APPLICATION man APR.16,1919.

Wnes l Inventor my f7/WM, /M /SMW J. BECKER.

PHOTOGRAPHIC CAMERA.

APPLICATION FILED APR. I6, 1919.

2 SHEETS-SHEET 2.

1 ,348, 888. Patented Jun@ 15, 1920.

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UNITED STATES `PATENT l OFFICE.

JOSEPH BECKER, OEwAsnINeTON, DISTRICT OE COLUMBIA, AssIGfNoR To EASTMANKODAK COMPANY, or .ROOHEs'rEa NEW YORK, A CORPORATION OE NEW YORK.

,PHOTOGRAPHIC OAMERA.

` Spcifcatqnpf Letters Patent Patented June 15, 19.20'.

original application inea December 11, 1915, serial 110.66371. Dividedand this application med April 1e, 1919. seriaiNo. 299,456.`

T 0 all ywhom 'it may concern Be it knownthat I, JOSEPH BECKER, acitizen of ,the United States, residing at Washington, inthe District ofColumbia, have invented certain new and useful Improvements inPhotographic Cameras, of whichth'e followingis a speciication.

My present application, identified for convenience of reference in myrelated applications or patents as Case Be, is a division of my priorCase Ate, which is noW Patent No. 1,301,897 granted Apn29, 1919.

My present invention relates to copying or enlarging cameras, and itconsists in the separately patentable type ,ofioptical foeuser disclosedin Figures 10 to 13 of my said Case Ae, and which is there designated asan optical Vtocuser of the fsingle .sight type. The principle involvedin my focusers of the single sight type is the same as thatl involved inreading time on a clock dial.

When the minute hand of a clockis set to indicate, for instance, nineminutes after the hour, the observer, holding .his eye in alinement withthe pivotal axis of the min-y ute hand, fsees the point 4of the minutehand in alinement with the 9-minute mark. If

his neye is laterally displaced with reference to the nine-minute axialis incorrect. e

Hence correct reading of the time depends upon the act of bringing intoroptical alinement three materialpoints, to wit: (1) the pupil of theeye; (2) the end of the` minute hand g and (3) the nine-minute ma-rk on'the dial; for when such optical alinement has been secured, the retinalimage of the minutehand end, and the retinalimage of the minute mark,are superposed, and

plane, his reading perfect registration or apparent coincidence isobtained 4within the observers eye.

A vmaterial peep hole, invariably fixed on the produced imaginarypivotal axis of the minutehand,f would insure correct placing of theeye, for all angular positions of the minutefhand.; but in most cases,'owingv to the vcloseness of the minute-hand end to the face of thedial, the eye is always placed sufficiently near to a correct positionwithout any special eye-positioning means, which would, however, becomeindispensable ifthe circular path describedby the minute-hand end werereally located at a considerable distance from vthe dint f VMy presentinventiomas stated above, involvesthe same principle, and it, therefore,

Consists in an Optical focuser that comprises` and it is ynotaconvenient practical form.

Hence, although I shall hereinafter make my `claim sufiiciently genericto ,include focusers of the class seen in the saidfCase Ae Fig. 10, I amusing for present purposes the preferable embodiment seen in Figs. 11

tol?) of said Case Ae. e

In the accompanying. drawings y Fig. 1, is a vertical axial section'of acopy# ing or enlarging camera having a preferred form of my single sightoptical focuser,

in which the structural point S will register optically Awith thestructural Vpoint V', as shown, whenever the camera is in focus on thevertical plane PV.

Fig. 2 isa similar view illustrating ad- `iustment number one, which ismade by focusing on left infinity; that is to say, by making PFOf Fig. 1infinitely long, so that FIP. must be equal to Zero.

, Fig. 3 is a second similar view illustrating adjustment number two,which is made On right hand infinity; that is to say, by making F Pinfinitely long, so that PF must be equal to zero.

\ Fig. 4 is a table of equations and dimensions. y y The bed of kthecamera is any truly planed heavy beam 1250 which is adapted to serve asa sliderail for the three camera frames 012, L12, Ilz, whose bases aregrooved to admit the beam so as to establish a smooth sliding e fit withits upper face and two side Jfaces. f-

The lens frame L1? is preferably fixed to the beam 125,0 by a screw1251, as shown, because the principles involved are more easilyunderstood whenthe lens is stationary, but such principles are simplydependent upon the relative movements of the three frames with relationto each other, and not upon the movements of any one of the three framesl with relation to any stationary base. Either Cil Csi

one of the end frames O12 or 112 might, theretore, be fixed to bed 1250in place of the lens frame, and the three trames U11, L12, 112, might beleft `tree to slide, if desired. Y

The top of the lens frame L12 is grooved to form. a smooth longitudinalslideway 1252 'for the foot 1253 of a bracket 1254. A screw passingfreely through a slot in foot 1253 serves to clamp the bracket 1254 inany desired longitudinal adjustment on the lens frame L12.

A pin 1220 whose axis is represented by a dot D is mounted in thebracket 1254 to serve as a pivot tor the radial cam sector 1218, whichis substantially the same as the sector 618 of my Case Ae Figs. 5 to 10,except that the right hand arm is converted into an alidade or sightingarm 1216' with a peep sight at D and a bead sight at S. This sightingarm 1216 has a hole 1217' which is adapted to register with either oneof. two similar holes'1240, 1240 bored in the bracket 1254. These holes1240, 1240' are so located that when the sector 1218 is set to make bore1217 register with bore 1240, as in Fig. 2, the radial arm 1216 pointsto left infinity; and it may be temporarily locked inv such position byinserting the bolt or pin 1241, as shown in Fig. 2. On the other hand,when the sector isset to make bore 1217' register with bore 1240', as inFig. 3, the radial arm 1216' points to right infinity; and it may betemporzuily locked in such position by inserting the same bolt or pin1241, as shown in Fig. In Fig. 1 the pin 1241 is shown as partlyinserted through the back into hole 1240', where it may be kept when notneeded.

The top of the object frame Ol2 is grooved to form a smooth longitudinalslideway 1262 for the foot 1263 of a bracket 1264. A screw 1265 passingfreely through a slot in foot 1263 serves to clamp the bracket 1264 inany desired longitudinal adjustment on the object trame O12.

The bracket 1264 is provided with an inciined groove 1215 correspondingin every particular to the groove 1015 ot the Case Ae Fig. 10, andhaving its imaginary terminal at A. Terminal A, which is alined withgroove 1215 at the same level as D in bracket 1254, remains in fixedrelation to its bracket 1264 and Jfollows the bracket 1264 in all itsadiustments and movements.

A pintle 1219, mounted 'tor adjustment in groove 1215 and whose axis isrepresented by a dot V, may be clamped to bracket 1264 at any desireddistance AV from A.

The image frame 112 isany block adapted to support the removablefocusing screen 1201 which corresponds to the similarly removablefocusing screen 1201 of the object frame.

Anyl point V' of the image planePthat is lower than the horizontal lineAD, Fig. l,

may be selected as the imaginary pintle V' corresponding to the pintle Vof the mechanical focuser seen in the Case Ae Fig. 10. The vector V'A,with A' at the level of D, but in fixed relation to plane 1)', atdistance m' therefrom, constitutes the imaginary terminal A of the imageframe 111. The exact }')osition oit A' is determined by the conditionthat the vector' VA' and groove 1215 or vector VA must be equally andoppositely inclined in accordance with the Case Ae equation 11 and asindicated in Fig. 4; and this makes V'A' invariable both as toinclination and length so that terminal A moves with plane 1)' as if VAand the upper m in Fig. 1 together constituted a rigid bracket. Inpractice no attention is paid to terminal A', which is introduced 'forthe sole purpose of illustrating the principles involved.

The adjustments to secure S-and-all point correspondence with any givenlens 509 are substantially the same as those described above for themechanical focuser of the Case Ae Fig. 10, but it will be well toredescribe them in detail.

Adjustment No. lh The m equal w adjustment is the one that must be madein the first place, because m is invariable, and we must first satisfythe equation 13 by making a" equal to m'.

The image Jiramc 112 is set and temporarily clamped in focus en lettinfinity, as seen in Fig. 2, to bring P' into coincidence with F andthus reduce the Newtonian space F'P' of the lens to zero value.

The sector 1218 is now set with its arm 1216 pointed to left infinityand its temporarily held in such position by insertion or" the bolt 1241as described above and as shown in F 2.

Screw 1255 is then loosened, and with his eye at E, te sight along theradial arm 1216', the operator slides the bracket 1254 along on the lensframe L12. This motion translates the sighting line DS horizontally, andcauses the point where this sighting line meets the vertical image planeP to move vertically. The operator, therefore, can always easily set thebracket 1254 so as to bring the sighting line DS onto any desired pointof the image plane F', such as the point V' here selected, 'forconvenience, in the upper edge et the plane.

Vi'hen the operator has thus found the proper position of bracket 1254,which that shown in Fig. 2, he firmly clamps the bracket 1254 to thelens :trame L12 by tightening screw 1255.

Terminal A now evidently coincides with D and the Newtonian space DA' ofthe mechanism has been made equal to Zero or equal to the present valueof; the Nev-.itcnian space FP' ofi' thelens. At vthe same time theimaginary bar was varied in length to make it yequal to the imaginarybar m, or, in the present case, equal to 37 `centimeters. d l n If thetemporary clamp used -tohold the image frame k112 be removed, Vsuchframe may now be slid rolf to any distance toward the right. In movingto the right it carries its points P and A" away from the stationarypoints F and D through distances FP and DA' that are necessarily equal,and we, therefore, know that the right hand Newtonian space DA of themechanism must henceforth be and remain equal tothe right hand Newtonianspace FP of the lens, as required by equation DAzFP.v now proceed withadjustment No. 2.

Adjustment No. 2-,In` making adjustment No. 1 the bar m was varied tomake it -equal to bar m', and this 'operation vnecessarily varied bar toina-ke it equal to FF minus In thel second adjustment, therefore, we areto-satisfy equation 12 by varying bar m to make it'equal to or, inthepresenticase, equal to 17 centimeters.

This is done as illustrated in Fig. 3. The object frame O12 is set andtemporarily clamped in focus on right infinity, as seen in Fig. 3, tobring Pinto lcoincidence with Fand reduce the Newtonianfspace PF of thelens to zero value.v d y The'sector 1218 is now set with its arm 1216pointed to right infinity, and itis temporarily held injsuch position bylinsertion of thebolt 1241; Y-

Screw 1265 is then loosened, vand the bracket1264 `is slid alongcon theobject frame O, which meanwhile-remains stationary, as it is temporarilyVclamped to vbase 1250-.: Y v

rThe bracketl1264 can thusbe shifted until Vits groove 1215 lregisterswith Vslot`1217 infami-1216, and whenlthis registration has beeninsured,by the insertion of pintle 1219 or V at any arbitrarydistance AV fromthe screw V1265 is firmly tightened to .clampv bracket 12.64 in itsthusself determined adjustment on the lobject frame' O22.'- It should benoted thatwhen the radial cam occupies its present position of Figi?) itfis capable of registering'with pintle'Vin any subsequently yselectedposition of`v V, so that the present adjustmentis in no way infinencedby the later or third adjustment,

which determines the value of AV.

, Terminal A now evidently coincides with D and the Newtonian space ADofthe mechanism has beenymade equal to zero, or

equal to the present value ofthe Newtonian space PF of the lens;

"At the same time the imaginary bar m was varied in length tomake itequalto the imaginary bar m, or, in the present` case, equal to 17centimeters..

If the temporary clamp used to hold the` object frame O12 be removed,such frame We can determined.

ldjusmnemf No. Sri-The object of thisadjustment-is to locate V in itsgroove 1215 sol that the product AV.AV shall be'fequal to the square-.ofthe focal length of the lens in acordance with the Case Ae equation 14.

'i This is done automatically yas follows: The end frames O12, vIlareset and tempo.-

rarily clamped in focus Yon each other, say

in the position of Fig. 1,*without payingV any attention to the exactkvalue of the copying factor; and when this has been done the' Case Aeequations 11,12, and 13 are all satisfied, and nothing more remains Vtobe done except to satisfy the Case Ac equation 14 by :properadjustmentof Athe distance AV, as AV is invariable, and, therefore', pre- PintleyV either i to `shorten or to lengthen the distance AV in Fig. 1,thesector 1218 is turned oniits :pivot D and thesighting line DS 4ismadel to sweep over the point V" inplane P. Pin V can, therefore, besetso as Etomake--the is, therefore, loosened along in its VgrooveV1215, andas it moves,

sightingline DS point directely at V and when this position of V hasbeen lfound piny tle'l219 is V'firmly clamped to 'bracket1264 at vitsthus self `determined proper distance from terininal'A.v v

The temporarary clampsjusedto hold the' end frames Om, Il? yin focus oneach other may now be removed'and .the ,device is'ready for use..` n d Yd VUse of he` Fig..1V @amant-TA characteristic feature `ofthe .opticallfocuser, Fig. 1, is that it leaves the three kcamera frames Q12, L12,T12 independent, tobe 'relatively displaced, as freely vas, if thefocuserwfere absent. Y

As a` rule, therefore, the image is out. of

focus, andV this is indicated bythe fact lthat Y the three points D, S,and V are generally out of alinement. V f

It is always easy, however," to secure sharp focus by displacing one ormoremof the frames so as to bring the three points D,

S, andrV4 into the focus indicating relation; that is to say, intoalinement.

Y Thus where the lens frame ,L12 is stationary, Aas in Fig. 1, theoperator can secure alinement, and hence focus, by shifting either oneof. the two; end frames without moving the other.

If he leaves the object frame O12 station-k ary the line of sight DSremains fixed, and with his eye at E he can by means of rope and pulley,o1' some equivalent gear, shii't the image frame Iig along on bed 125()until point V falls into the sighting line DS.

If he prefers toleave the image frame 112 stationary he must securefocus by moving the object frame O12. Moving the object frame O12 makessector 1218 turn on its pivot D and causes the sighting line DS to sweepover the image field. I-Ie can, therefore, easily set the object frameO12 so as to point the sighting line DS directly at V', wherever Vhappens to bve.

Point V in Fig. 1, throughout all its movements, remains at a constantlevel or distance below the horizontal plane that contains the threeaxes A, D, A. Let this distance be called 12,.

Then L is evidently equal to AV multiplied by the sine of angle delta(A) but in reality 7L and delta (A), being both invariable, predetermineAV, for

cam focuser may be made like the twosight focuser seen in my CaseAe--Fig 16,

so that its sighting arms DS shall point rearwardly toward the eye,instead of toward the object. The structural sector angle of the focuserthen becomes equal to the acute angle supplement of the obtuse basicangle delta No'rE 2.While the obtuse angle type of radial camv focuseris preferred, for present purposes, there are special uses of theinvention in which a basic angle delta (A) that is equal to a rightangle, or even smaller than a right angle, may present practicaladvantages; hence I make but one claim that is limited to the obtuseangle type.

NOTE 3.--I, moreover, do not limit my invention to focusers of theradial cam type, for it is quite evident that, in any form or type ofaccurately designed mechanical focuser, the judicious severance of onemechanical connection is suiiicient, as in my case Ae Fig. 10, toconvert such mechanical focuser into a single sight optical focuser,which, as a rule, will focus more precisely than the wholly mechanicalfocuser, because it is relieved of all stresses and resultant strains.

NOTE l1.-My Case Ae explains that the stresses, just referred to, may beso large in an obtuse angle radial cam mechanical focuser, as to renderthe device inoperative. But any such inoperative obtuse angle radial cammechanical focuser may be rendered operative by converting it into asingle sight optical form, as explained in Note 3, above. Hence I ammaking, in the presentCase Ae,

my broadest claim to a copying or enlarging camera having a radial camfocuser whose basic angle delta (A) is obtuse.

NOTE 5.No attempt has been made to show a compact arrangement which isalways easily obtained by mounting the focuser flat against anypreferred one of the iour sides of the camera, either top, bottom,right, or left, as proposed :lor my linkage focuser in my Case K, nowIatent 1,103,342, issued. July 111, 1914, page 7, lin'es 24 to 31. Theright hand side of the camera is shown used in Fig. 16 of my said parentapplication, Case Ae, :for a radial cam focuser of' the two-sight type.

Vhat I claim as my invention and to secure by Letters Patent is:

1. The combination, with a copying or enlarging camera comprising threerelatively movable frames, to wit: (l) an object frame; (2) a lensiframe; (3) and an image frame; also means for relatively guiding desiresaid three frames `to permit of placing and holding them in anyconjugatel relation necessary to secure the sharpest image of anydesired size; of an optical focuser for said camera, adapted toindicate, by single sight, at all times, and for all positions oi thesaid three camera frames, the exact focal condition of the camera; saidfocuser comprising twoV relatively movable structural points; alsoconnections between said .two structural points and the said threecamera frames, such that said two structural points shall be in apparentregister or alinement whenever, and only when, the said camera is infocus.

2. A structure comprising the elements of claim 1; and, in additionthereto; a third structural focuser point which is adapted to locate theobservers eye in a position that avoids parallactic error in readingthe. relative position of the said first two structural,focusindicating, focuser points.

3. A structure comprising the elements of claim 1; and, in additionthereto: normally rigid but dimensionally` adjustable structuralelements, each element composed of two parts that are adapted to beclamped in any relative position that sets a dimension, of said element,at any conceivable value that may be required to suit the dimensions ofany one of diiferent lenses.

4;. A copying or enlarging camera having a focuser which is of theradial cam type, and whose basic angle delta (A) is larger than a rightangle.

In testimony whereof, Iy have signed my name tothis specification in thepresence of Mrs. MARY E. CowELL as a witness.

JOSEPH BECKER.

Witness:

MARY E. CowELL.

